-In a large bowl cream butter and sugar. Add egg and vanilla and mix until smooth

-In a small bowl mix flour and baking powder. Pour half of the flour mixture into the creamed butter, sugar & egg mixture

-Stir gently until flour is incorporated. Repeat with remaining flour. Once mixed together, form into a ball. Place ball on sheet of parchment paper (works best if parchment has been dusted with flour)

-Sprinkle flour on top of ball and then cover with top sheet of parchment. Roll out dough (between sheets of parchment) to 1/4'' thick

In a large bowl, mix ingredients until smooth and glossy in appearance. Add food coloring as desired. If too thick, add small amount of milk or corn syrup (1/4 tsp at a time). Icing will harden as it sets.